package com.tang.Date20240613;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @author tmh
 * @date 2024/6/13 22:15
 * @description
 */
public class ConcurrentHashMapDemo {
    public static void main(String[] args) {
        ConcurrentHashMap<String,String> map = new ConcurrentHashMap<>();
        map.put("1","1");
        Map<String,String> hashMap = new HashMap<>();
        hashMap.put(null,"suyu");
        System.out.println(hashMap.containsKey(null));
        System.out.println(hashMap.get(null));
    }
}
